It looks like Apple is moving away from the L-shaped logic board design for the iPhone XI and back to a standard, rectangular one.
The proof is in a few images of the logic board of the iPhone XI from a few different sources.
The iPhone X/XS had a stacked L-shaped logic board which pushed the battery to also be L-shaped. With the iPhone XI Apple will move to a rectangular logic board and a large rectangular battery to the side of it.
We expect the iPhone XI and XI Max to have bigger batteries as a result of the new logic board design.
Sadly we can't gain any information from the PCB design. Questions about the iPhone XI's port of choice are still looming. We already know what the iPhone XI and XI Max will look like, but hardware info is rather limited at this point.